Effect of pectinase treatment on extraction of antioxidant phenols from pomace,for the production of puree-enriched cloudy apple juices

Effects of pomace maceration on yield, turbidity, cloud stability, composition of phenolics, antioxidant activity and colour properties were studied, to evaluate the potential applicability of enzyme preparations in puree-enriched cloudy apple juice production. The yield of mixed juice and puree from pomace obtained in the enzymatic processing of apple ranged from 92.3% to 95.3%, significantly higher than the yield from the control without enzymatic pomace treatment (81.8%). Higher turbidity was obtained upon pomace treatment with Pectinex XXL and Pectinex Ultra SPL enzymes. The total content of phenolic compounds in apple pomace was higher than in raw juices (1520 mg/kg and 441 mg/L, respectively). The total polyphenol yields were higher in juices treated with Pectinex AFP L-4, Pectinex Yield Mash and Pectinex XXL, as compared to the control treatment. During 6 months of storage, a significant change was observed in the content of polyphenols, especially in procyanidin fractions.     

Chemical composition and physical properties of modified dietary fibre sources

The influence of thermal treatments on the chemical composition and the physical properties of yellow pea hulls, apple pomace and depectinised apple pomace were determined. The chemical composition of yellow pea hulls and apple pomace was altered only slightly. With depectinised apple pomace, however, the heat treatments led to a significant loss of the total dietary fibre (TDF) content. Water uptake, water binding capacity, rheological behaviour in the farinograph and oil absorption were determined before and after boiling, autoclaving and extrusion cooking. The physical properties of all samples were considerably affected by the thermal modifications. Whilst in cooked dietary fibre samples the water uptake, the water binding capacity and the oil absorption was always enhanced, the influence of autoclaving and extrusion cooking on the physical properties depended very much on the dietary fibre source. Yellow pea hulls showed unchanged or slightly increased values, while the results for the two apple pomace preparations were lower compared with the untreated samples. The differences in the farinogramsiwere less obvious since the dietary fibre content in the dough mixtures was only in the range of 10–20%.     

ROLE of CULTIVAR and PRESS AID IN PRESSING CHARACTERISTICS and JUICE YIELDS of CRUSHED GRAPES

The stress-volume characteristics of crushed grape cultivars: Baco Noir, Cabernet Sauvignon, Catawba, Cayuga White, Chardonnay, Concord, Delaware, Melody, Niagara, Johannisberg Riesling, and Seyval Blanc, with and without paper and rice hulls press aids were studied in an expression cell and an Instron Universal Testing Machine. the slopes of ln stress vs volume in compression were significantly (P< 0.001) dependent on the grape cultivar. Addition of 1–3% press aid by weight decreased the magnitudes of slopes by about 11% with Seyval Blanc to about 51% with Catawba; i. e., the ease with which pressing could be performed increased with the addition of press aid. With Cabernet Sauvignon grapes, addition of press aid 0.5, 1.0, and 2.0% resulted in increase in slopes ranging between 14.7 and 24.9%. the slopes of the ln stress-ln time during the relaxation portion of the experiment were also significantly dependent (P< 0.001) on the grape cultivar; the magnitudes of the slopes increased with the addition of 1–3% paper press aid. the juice yields were affected significantly (P< 0.001) by the addition of paper press aid, with maximum yields being obtained when 1–2% (w/w) paper press aid was added. As expected, juice yields (w/w%) were significantly dependent (P< 0.001) on grape cultivars.     

PESTICIDE RESIDUES IN BEEF TISSUES FROM CATTLE FED FRUITS, VEGETABLES AND THEIR BYPRODUCTS

Muscle, adipose, liver and kidney tissue samples were collected from cattle fed potato processing residue (n=20), apple pomace (n=20), pear pomace (n=10), cannery corn waste (n=20), cotton gin trash (n=20), tomato pomace plus almond hulls (n=16), dried grape solids (n=10) or dried citrus pulp (n=6) as well as from control cattle which were not fed fruits, vegetables or their byproducts (n=21). All adipose tissue samples (n=143), representative samples of the above feeds (n=24) and representative samples of muscle (n=35), liver (n=35) and kidney (n=35) tissues were assayed for acephate, benomyl, captafol, cypermethrin, folpet, azinphos-methyl, captan, chlorothalonil, ethyl parathion, and permethrin. In 2,720 tests for the aforementioned oncogenic pesticides, eight tests were positive, but no residue amount that would be considered violative was detected. The only pesticide detected was benomyl and it was detected at nonviolative levels in the adipose tissue of cattle that had been fed either apple pomace or pear pomace.     

Apple pomace liquefaction with pectinases and cellulases:analytical data of the corresponding juices

Apple juices were produced by way of a two-stage process consisting of traditional enzyme treatment of the mash with pectinases for the premium juices and pomace liquefaction with different pectinases and cellulases for the extraction juices. Premium and extraction juices were analysed separately. Calculated to an equal juice strength of 12° Brix, there was an increase of D-galacturonic acid and cellubiose in the extraction juices. Released galacturonic acid from cell wall material was found at levels ranging from 107 mg/l to 1239 mg/l. This was an essential contribution to the total titrable acid of the extraction juices. The sum of phenolic substances determined by high performance liquid chromatography was significantly higher in all the extraction juices than in the corresponding premium juices. Among the phenolics, the dihydrochalcone phloretin 2′-glucoside (92–110 mg/l) showed an increase of 4 to 5 times the concentration in the respective premium juices. Quercetin derivatives were mainly present in the extraction juices; here the values were between 32 mg/l and 38 mg/l. Under the influence of strong pectolytic or cellulolytic enzyme activities, oligo- and polysaccharides are released from the apple cell wall material, resulting in colloid concentrations of up to 15 g/l in the extraction juices. High concentrations of polyphenols and pectic polysaccharides can lead to technological problems. However, pomace liquefaction may also turn out to be suitable for obtaining value-added foods. In respect to nutritional aspects, enzymatic treatment of pomace offers the opportunity of releasing apple polyphenols and polysaccharides contained in the pomace to a greater extent and obtaining them preparatively. Received: 2 December 1999     

Unrefined, Dried Apple Pomace as a Potential Food Ingredient

Unrefined pomace of three apple cultivars was dried, powdered, analyzed and evaluated in pie filling and oatmeal cookies. Pomace had 2.2 - 3.3% seed, 0.4 - 0.9% stem, 70.0 - 75.7% apple flesh and 20.1 - 26.4% rice hull as filtering aid (DWB). Average dietary fiber was 36.8% and remaining carbohydrates were 54.4%, totalling 91.2%. Remaining components were protein, fat and ash. Average pH was 4.3; water activity, 0.13; and WHC, 3.7 mL/g. Hunter color was L = 51.8, a = 5.4, and b = 18.2. Two levels of pomace in pie filling or three levels in oatmeal cookies did not affect color, cookie size or sensory scores. Both food products were rated as liked moderately.     

纤维素酶提取苹果渣黄酮及抗氧化研究

研究了纤维素酶提取苹果渣黄酮的工艺条件及抗氧化活性。结果表明,与传统化学法相比,纤维素酶法提取苹果渣黄酮较好,黄酮提取率从0.43%提高到0.56%。对酶法提取工艺进行优化,得到最佳工艺条件为:纤维素酶浓度0.2%,pH=5.2,酶解温度60℃,酶解时间40min。在最佳条件下,纤维素酶法所得黄酮的提取率可达到1.26%,为化学法黄酮提取率的2.93倍。并对提取的黄酮进行羟自由基清除实验,发现酶法与化学法提取黄酮的成分清除能力相似,表明两种方法提取黄酮物质结构可能一样。     

Apple pomace in gluten‐free formulations: effect on rheology and product quality

The objective of the present work was to formulate a gluten‐free (GF) baked product based on a cassava starch, rice flour and egg white mixture and enriched with apple pomace with minimum processing as source of fibre. Effects of apple pomace and water amount on batters and product quality were analysed by response surface methodology (RSM). Dynamic moduli of batters, specific volume and crumb texture were highly dependent on both apple pomace and water. Higher levels of fibre rendered less cohesive and less resilient crumbs and diminished specific volumes. A suitable balance between amounts of apple pomace and water led to products with enough specific volume and sponginess. Up to 12.5 g apple pomace and water ranging from 115 to 150 g (each 100 g mixture), specific volumes were maintained higher than 2 cm³ g^?1; if apple pomace was increased up to 20 g, water amounts higher than 140 g were necessary to obtain similar results.     

A Solid State Fermentation System for Production of Ethanol from Apple Pomace

A solid state fermentation system for the production of ethanol from apple pomace with a Montrachet strain of Saccharomyces cerevisiae is described. The yields of ethanol varied from about 29g to more than 40g per kg of apple pomace, depending on the samples fermented. Separation of up to 99% of the ethanol from spent apple pomace was achieved with a rotary vacuum evaporator. The results of this study indicate that the alcoholic fermentation of apple pomace might be an efficient method of alleviating waste disposal problems with the concomitant production of ethanol.     

CaCl_2对苹果酒酿造的影响

对以红富士苹果为原料 ,分别添加 0 3、0 4、0 5g/LCaCl2 的澄清苹果汁进行了研究。清汁中接种酿酒酵母Aw(Saccharomycescerevisiae ,Aw) ,于 2 0℃控温发酵 ,陈酿、澄清后进行理化、感官分析与风味物质测定。研究显示 ,添加CaCl2 显著地提高了果汁的澄清度、加快了果汁澄清速度。果汁处理时间低于 12h时 ,CaCl2 加量以 0 4g/L为宜 ;处理时间在 18～ 2 2h ,CaCl2 加量为 0 3～ 0 5g/L。经CaCl2 增加酸度 ( 1 49～ 1 5 7g/L)、降低 pH值 ( 0 19～ 0 2 4)、对酵母酒精发酵、发酵过程中滴定酸和 pH的变化趋势无显著影响。CaCl2 处理的果汁发酵的苹果酒滴定酸度高、残糖低 ,总浸出物低 ,酒精浓度与未处理苹果酒接近 ;口味纯正、爽口 ,色泽好 ,果香味突出。     

Effect of clouding agents on the quality of apple juice during storage

Apple pomace, (AP) was subjected to evaluation as potential source of clouding and antiradical agent in cloudy apple juice (CAJ). The evaluation was carried out in comparison with three hydrocolloids, namely sodium carboxymethyl cellulose (CMC), xanthan (XA), and pectin (P). The quality parameters of cloudy apple juice such as cloud stability, viscosity, phenolic content, sensory evaluation and antioxidant activity had been studied since these parameters control the consumer acceptance of that product. All the analyses were carried out for fresh and treated juices after storage at 4 and 25 °C for two weeks. The cloud stability of juices added decreased quickly and remained more stable than the untreated treatment. However, the hydrocolloids showed significant (P < 0.05) increase in viscosity, they exhibited deterioration in sensory attributes. The results indicated a good correlation between phenolic degradation and the radical scavenging activities.     

Effects of various clarification treatments on phenolic compounds and color of apple juice

The purpose of this study was to investigate the changes that occur during conventional clarification using gelatin, bentonite, silica sol, and water-soluble chitosan on the phenolic compounds, antioxidant activity, and color of apple juice. The apple material used in this study was of two varieties: Sampion and Idared. The changes in the polyphenols composition (procyanidins, hydroxycinnamic derivatives, and dihydrochalcones) were monitored through the clarification process. Sampion apple control juices contained more total polyphenols than do Idared apple juices. In Sampion variety apple juice, the dominant polyphenols are the flavan-3-ols (86% of total polyphenols), followed by hydroxycinnamic acids (9.7%), dihydrochalcones (3.0%), and flavonols (1.3%). In Idared apple juice the hydroxycinnamic acids (especially chlorogenic acid) are dominant (about 48% of total polyphenols), followed by flavan-3-ols (40%). However, the concentration of polymeric procyanidins in Sampion apple juices was 62.8 and 46.3% less when the Profloc (chitosan) and gelatin treatments were used, respectively. Aktivbentonit and Puranit (bentonite) supplementary added in juices clarification have some protective effect on polymeric procyanidins only with Profloc treatment. That kind of effect was not observed in Idared apple juices with almost eight times smaller polymeric procyanidins concentration than in Sampion apple juices. The antioxidant activity, measured by the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) method, ranged from 0.20 mg TEAC/mL in Idared apple juice to 0.30 mg TEAC/mL in Sampion apple juice, measured by the ABTS method, from 0.17 to 0.48 mg TEAC/mL, respectively. Clarification of apple juices with chosen clarifying agents has statistically no significant (p>0.05) influence on antioxidant capacity. This study suggests that chitosan can be used as a conventional clarifying aid of apple juices and that treatment has no impact on their biochemical parameters.     

Cross-flow Microfiltration with Gas Backwash of Apple Juice

Cross-flow microfiltration (MF) was applied for clarification of commercially pressed depectinized apple juices and pectin containing artificial apple juice suspensions under continuous low pressure inlet conditions (35 kPa - 209 kPa). Periodic gas backwash (air or N₂) removed solids from exteriors of 0.2 μm cut-off hollow fiber polypropylene membranes. Flux and nephelos turbidity units (NTU) of filtrates for both commercial juices and artificial juices were evaluated. Commercial juices after vacuum filtration and MF had 100–110 L/m²/hr flux during 2 hr operation. Low pectin (1%) artificial juices had ～70 L/m²/hr flux during 1.5 hr. NTUs of filtrates from all treatments were <0.69. All filtrates were commercially sterile.     

植物性食品加工副产物的综合利用和开发的现状

对玉米麸皮、米糠、麦麸、胡萝卜渣、葡萄皮渣、苹果渣等一些植物性食品加工过程中产生的副产物的综合开发利用问题予以综述,探讨了在食品工业、医疗、化工等方面的应用,并对其开发利用前景进行了展望。     

苹果鲜渣保藏及其发酵分析

以秦冠苹果渣为原料,采用稀释平板法和HPLC分别对发酵苹果渣的微生物及有机酸组成进行了分析,并对不同发酵方式进行了比较。结果表明,发酵苹果渣中主要微生物是酵母菌、醋酸菌和乳酸菌。苹果渣发酵产物中的有机酸主要是醋酸和乳酸,分别占有机酸总量的45.840%和44.746%,发酵苹果渣中尚未发现有害菌。发酵果渣的蛋白质含量较未发酵果渣有较大的提高;采用不同方式发酵的果渣,其蛋白质含量有较大差异,其中以露地薄膜法发酵的蛋白质含量为最高,且氨基酸组成较为合理,优于小麦蛋白。     

基于品质指标的苹果浊汁品种与产地差异性分析

以来自7?个不同主产区的21?个主栽品种,共41?份苹果鲜果为研究对象,对每个品种鲜榨浊汁的出汁率、浊度、果汁颜色、褐变度、透光率、可溶性固形物、可滴定酸、总酚、糖、有机酸、VC、矿物质、抗氧化性等品质指标进行测定。运用描述性分析、逐步线性判别分析进行数据处理。结果表明：不同品种或不同产地的苹果浊汁,品质差异较大。总体来看,a*值、原始浊度、褐变度、可滴定酸、葡萄糖、蔗糖、苹果酸等指标的变幅均较大,分别为94.07%、70.41%、42.86%、35.26%、42.02%、42.40%、37.69%。对于不同品种的苹果浊汁,由于褐变度、总酚、抗氧化性等色泽品质指标以及糖、酸等营养品质指标间具有较大差异,其分布呈现分散状态。其中新红星品种的褐变度、总酚含量、DPPH自由基清除率等品质指标普遍居高,色泽品质差异最显著。富士品种大部分样品的果糖、葡萄糖、蔗糖、苹果酸等指标含量较高,具有较好的营养品质。然而对于不同产地间的样品,其浊度、可滴定酸、可溶性固形物等加工品质指标具有较大差异,样品分布较为分散。河北省样品的出汁率、原始浊度、可滴定酸等指标普遍较低,加工品质较差。来自山东省不同品种苹果浊汁的样品以及来自不同产地富士苹果浊汁的样品间均具有较大差异,并且分别获得了77.8%和72.7%的判别准确率。以上结果表明,不同产地、不同品种苹果原料制得的苹果浊汁存在较大差异,通过对其品质指标进行差异性分析,可为上游育种与种植产业结构调整提供数据基础;通过判别模型的建立实现品种与产地的识别与预测,可以指导企业对苹果原料进行制汁专用化筛选。     

Effect of extraction conditions on the yield and purity of apple pomace pectin precipitated but not washed by alcohol

ABSTRACT:  A study of the influence of extraction conditions (pH: 1.5 to 2; temperature: 80 to 90 °C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of impurities by alcohol washing was carried out. The alcohol precipitate yields varied from 2.9% to 8.9% depending on the pH. At pH 1.5, these yields were higher than those obtained at pH 2 contrary to the galacturonic acid purity (%w/w). Compounds other than pectins were solubilized from the cell walls of apple pomace at pH 1.5, and they were precipitated with alcohol. The apple pectins obtained from the different extraction procedures were highly methylated (54.5% to 79.5%), especially when the conditions (temperature, pH) were drastic. Similar conclusions can be drawn for the neutral sugar content that decreased at pH 1.5 (arabinose, xylose, and galactose) or at the highest temperatures and extraction times (arabinose and galactose). The phenomenon of demethylation and pectin degradation of neutral sugars chains can be observed at acid pH, and for long extraction times. The presence of high quantities of mannose or fructose, glucose, and xylose in the alcohol precipitate showed that pectin precipitation with ethanol was not specific.     

四种小浆果浆汁活性成分及其抗氧化活性

为了对树莓、蓝莓、黑果腺肋花楸及蓝靛果四种小浆果浆汁进行初步活性评价,测定了四种小浆果浆汁的多酚、超氧化物歧化酶(SOD)、花色苷及总黄酮含量,并研究其体外抗氧化活性。结果发现,蓝靛果的多酚(4.659 mg/mL)、SOD(115.38 mg/mL)及总黄酮(10.717 mg/mL)是其他三种小浆果含量的1.5~7倍,花色苷(3.768 mg/mL)则是黑果腺肋花楸含量的14倍左右。以V_C作阳性对照,蓝靛果体外抗氧化效果最优,对·OH、DPPH·自由基的清除及对脂质过氧化的抑制作用的IC₅₀值分别为2.066 mg/mL、61.342 μg/mL和181.590 μg/mL,对O₂-·自由基的清除效果并没有明显优势。活性成分含量与抗氧化活性相关性分析表明,四种小浆果浆汁中多酚、花色苷、SOD及总黄酮含量与对·OH、O₂-·、DPPH·自由基的清除率及对脂质过氧化的抑制率均呈正相关性,且相关性显著。四种小浆果浆汁均具有较好的体外抗氧化活性,蓝靛果显示了最佳的抗氧化活性。     

Effects of different enzymatic maceration treatments on enhancement of anthocyanins and other phenolics in black currant juice

Pre-press maceration treatments with 10 different pectinolytic enzyme preparations were investigated in experimental black currant juice production using response surface design templates. Enzyme dosage, maceration time, reaction temperature, and degree of berry crushing were varied, and the juice yields, anthocyanins, total phenols, and turbidity in the resulting juices were compared for a total of 250 different enzymatic treatments. The yields of anthocyanins and total phenols in the juices ranged from 900 to 2200 and 3050 to 5100 mg/kg wet weight black currant mash, respectively. Juice yields ranged from 66.4% to 78.9% by wet weight of mash. Turbidity levels ranged from 25 to 916 formazan nephelometric units (FNU). The reaction parameters induced larger variations in the responses than the different enzyme preparations, but the cloned Aspergillus niger/Aspergillus aculeatus preparation Pectinex BE® consistently tended to be among those giving the best responses regarding anthocyanin yields, phenols, and low juice turbidity. The optimal maceration was achieved using an enzyme dosage of 0.18% by wet weight of berries with a reaction at 60 °C for 30 min on the most finely crushed berry mash. This treatment gave similar profiles of anthocyanins in the juices with all the 10 enzyme preparations. The same 10 juices all exhibited antioxidant activity against human low-density lipoprotein oxidation in vitro, but the antioxidant potency varied depending on the enzyme preparation used in the pre-press maceration.     

Apple pomace as a source of dietary fiber and polyphenols and its effect on the rheological characteristics and cake making

Apple pomace, a by-product of apple juice industry, is a rich source of fibre and polyphenols. Also in view of the antioxidant property of pomace, it would play an important role in prevention of diseases. Apple pomace procured from fruit juice industry, contained 10.8% moisture, 0.5% ash and 51.1% of dietary fibre. Finely ground apple pomace was incorporated in wheat flour at 5%, 10% and 15% levels and studied for rheological characteristics. Water absorption increased significantly from 60.1% to 70.6% with increase in pomace from 0% to 15%. Dough stability decreased and mixing tolerance index increased, indicating weakening of the dough. Resistance to extension values significantly increased from 336 to 742 BU whereas extensibility values decreased from 127 to 51 mm. Amylograph studies showed decrease in peak viscosity and cold paste viscosity from 950 to 730 BU and 1760 to 970 BU respectively. Cakes were prepared from blends of wheat flour containing 0–30% apple pomace. The volume of cakes decreased from 850 to 620 cc with increase in pomace content from 0% to 30%. Cakes prepared from 25% of apple pomace had a dietary fibre content of 14.2% The total phenol content in wheat flour and apple pomace was 1.19 and 7.16 mg/g respectively where as cakes prepared from 0% and 25% apple pomace blends had 2.07 and 3.15 mg/g indicating that apple pomace can serve as a good source of both polyphenols and dietary fibre.